WASHINGTON: President Donald Trump said on Thursday (Jul 2) it is "ridiculous" for the United States to continue its "one-sided" relationship with NATO, less than a week before a NATO summit in Ankara.

Trump wrote on his Truth Social platform: "They were not there for us!!!" and Washington's relationship with NATO "is not reciprocal".

Trump has repeatedly lashed out at European allies over their response to the war in Iran, as several countries restricted the use of bases for US forces.

Trump also insists he wants Europe to take the lead role for its own defence, and Washington has already moved to scale back commitments.

His Truth Social post on Thursday included a chart displaying the amount of NATO spending, with the United States investing vastly more than a few other member states depicted.

Under pressure from Trump, NATO leaders had agreed at a gathering last year to boost defence-related spending to 5 per cent of GDP by 2035.

The upcoming NATO summit, which will bring together 32 member states, will be held in the Turkish capital on Jul 7-8.

The alliance, founded in 1949, became a US-led defence force credited with maintaining stability in Europe, keeping the Soviet Union at bay and solidifying Washington as a world power for decades to come.